Question 3.8: Classification of Chemical Bonds Classify each bond as nonpo...
Classification of Chemical Bonds
Classify each bond as nonpolar covalent, polar covalent, or ionic.
(a) \text{O}-\text{H} (b) \text{N}-\text{H} (c) \text{Na}-\text{F} (d) \text{C}-\text{Mg} (e) \text{C}-\text{S}
Strategy
Using Table 3.5, determine the difference in electronegativity between bonded atoms. Then, use the values given in Table 3.6 to classify the type of bond formed.
| Table 3.5 Electronegativity Values of the Elements (Pauling Scale) | ||||||||||||||||
|
7A |
6A |
5A |
4A |
3A |
2B |
1B |
(10) |
8B |
(8) |
7B |
6B |
5B |
4B |
3B |
2A |
1A |
| H 2.1 |
||||||||||||||||
| F 4.0 |
O 3.5 |
N 3.0 |
C 2.5 |
B 2.0 |
Be 1.5 |
Li 1.0 |
||||||||||
| Cl 3.0 |
S 2.5 |
P 2.1 |
Si 1.8 |
Al 1.5 |
Mg 1.2 |
Na 0.9 |
||||||||||
| Br 2.8 |
Se 2.4 |
As 2.0 |
Ge 1.8 |
Ga 1.6 |
Zn 1.6 |
Cu 1.9 |
Ni 1.8 |
Co 1.8 |
Fe 1.8 |
Mn 1.5 |
Cr 1.6 |
V 1.6 |
Ti 1.5 |
Sc 1.3 |
Ca 1.0 |
K 0.8 |
| I 2.5 |
Te 2.1 |
Sb 1.9 |
Sn 1.8 |
In 1.7 |
Cd 1.7 |
Ag 1.9 |
Pd 2.2 |
Rh 2.2 |
Ru 2.2 |
Tc 1.9 |
Mo 1.8 |
Nb 1.6 |
Zr 1.4 |
Y 1.2 |
Sr 1.0 |
Rb 0.8 |
| At 2.2 |
Po 2.0 |
Bi 1.9 |
Pb 1.8 |
Tl 1.8 |
Hg 1.9 |
Au 2.4 |
Pt 2.2 |
Ir 2.2 |
Os 2.2 |
Re 1.9 |
W 1.7 |
Ta 1.5 |
Hf 1.3 |
La 1.1 |
Ba 0.9 |
Cs 0.7 |
| Table 3.6 Classification of Chemical Bonds | ||
| Most Likely Formed Between | Type of Bond | Electronegativity Difference Between Bonded Atoms |
| Two nonmetals or a nonmetal and a metalloid | \left.\overset{\text{Nonpolar covalent}}{\underset{\text{Polar covalent}}{}} \right\} | Less than 0.5 0.5 to 1.9 |
| A metal and a nonmetal | Ionic | Greater than 1.9 |
| Type of Bond | Difference in Electronegativity | Bond |
| Polar covalent | 3.5 – 2.1 = 1.4 | (a) \text{O}-\text{H} |
| Polar covalent | 3.0 – 2.1 = 0.9 | (b) \text{N}-\text{H} |
| Ionic | 4.0 – 0.9 = 3.1 | (c) \text{Na}-\text{F} |
| Polar covalent | 2.5 – 1.2 = 1.3 | (d) \text{C}-\text{Mg} |
| Nonpolar covalent | 2.5 – 2.5 = 0.0 | (e) \text{C}-\text{S} |
■ Quick Check 3.8
Classify each bond as nonpolar covalent, polar covalent, or ionic.
(a) \text{S}-\text{H} (b) \text{P}-\text{H} (c) \text{C}-\text{F} (d) \text{C}-\text{Cl}